Expanding bearing pin



Patented Feb. 21, 1939 UNITED STATES EXPANDING BEARING PIN Quinten E.Conner,

Application March 15,

4 Claims.

This invention relates to improvements in expanding bearing pins.

Among the objects ofV this invention is to reduce maintenance expense ofmechanical equipment by minimizing labor costs for taking up wornbearings.

Another object is to provide a bearing pin suitable for use ininstallations having heavy bearing pressures.

Another object is to provide a bearing pin which will automaticallyexpand to progressively take up wear in the bearing as it occurs.

Another object is to lock the bearing pin in expanded position as itsexpansion progresses so as to prevent the bearing pin yielding andcontracting under pressure.

Another object is to prevent the automatic expansion of the bearing pinbeyond a given extent.

Another object is to provide simple manual means for allowing further-limited automatic expansion of the bearing pin after the pin hasexpanded to the extent originally permitted.

Another object is to insure adequate lubrication of the bearingsurfaces.

A further object is to provide a bearing pin sturdy of construction andpermanently reliable in operation.

Other objects and advantages appear as this description progresses.

In this specification and the accompanying drawings the invention isdisclosed in its preferred form. It is to be understood, however, thatit is not limited to this specic form because it may be embodied inmodications within the purview of the claims following the description.

In the two sheets of drawings:

Fig. 1 is a longitudinal vertical section of a bearing pin constructedin accordance with this invention.

Fig. 2` is a transverse vertical section of the same taken along theline II--II in Fig. 1.

Fig. 3 is a fragmentary detail View in horizontal section showing thelocking means for holding the pin in expanded position against bearingpressure.

Fig. 4 is a view similar to Fig. 1 of a modiiied form of the inventionembodied in a bearing pin which is manually adjustable to take up wear.

In detail the construction, illustrated in the drawings referring moreparticularly to Figs. 1 and 2, comprises the trunnion sleeve Iprojecting laterally from the member 2. In the present instance, themember 2 is a rotating member. It might, of course, be a stationarybracket in other 5 applications of the invention.

SanV Francisco, Calif.

1937, Serial No. 130,924 (Cl. 308-64) The bearing segments 3 slidablyengage the bushing 4 xed within the bracket 5. The adjoining ends of thebearing segments have the interlocking step cuts 3 therein to preventany incidental chattering thereof. The segments may be provided with thelips 6-6 to prevent longitudinal movement within the bushing should noother provision have been made for incidental lateral thrust. Thesegments have the central radial anchor lugs I extending through theslots 8 in the sleeve I. The inwardly disposed sides o! the lugs 'I areprovided with the V-shaped cam surfacesV 1.

The cylindrical blocks 9 and within the sleeve I and have the grooves IIand I2 engaging the ends of the lugs 1. The bottoms of the grooves areinclined upwardly to coincide with the slopes of the V-shaped camsurfaces 'I'. The blocks are recessed at I3, I4 tov receive the springI5 which expands therebetween. The blocks, when urged apart by theexpansion of the spring I5, co-act with the V-shaped ends of the lugs Iand move the segments 3 outward into frictional engagement with thebushing 4. The tension of the spring I5 is such that the outward forceexerted on the segments 3 is somewhat less than the mean opposed forcethereon applied by the bearing bushing 4. This prevents the segments 3expanding unduly and insures the proper Working clearance beingmaintained in the bearmg.

The axial stem I Ii is threaded at I I in the block 9 and slidablyextends through the block I0. The block I0 has the recess I8 therein toreceive the spring I 9 which expands outwardly against the Washer andlock nut assembly on the end of the stem I6. The spring I9 tends to urgethe blocks 9 and IIJ together counter-acting the effect of the springI5. In assembling the apparatus, the lock nut assembly 2i] is adjustedso that the spring I9 exerts less pressure than the spring I5. Thesprings, however, are so designed that the spring I9 requires more forceto compress it a given distance than does the spring I6. This differencein design of the two springs is an im portant factor in the operation ofthe invention, later to be described.

The abutting ends of the blocks have the opposed grooves 2I--22, 2I-22therein, see also Fig. 3. The ends of these grooves are closed by thestops 23 and 24. The wedges 25 in the grooves 2I are backed up by thesprings 26 expanding against the stops 23. These wedges cooperate withthe wedges 21 which occupy positions against the stops 24. It isrequired that I are slidable the tangent of the angle of the wedges withrespect to the transverse plane be less than the value of the coeicientof the friction therebetween. Thus designed, the wedges positively holdthe blocks 9, I apart no matter what force is exerted tending to bringthem together.

The end of the sleeve 2 is closed by the plate 29 which has the usualcoupling 30 therein for high pressure lubrication. The lubricantadmitted within the sleeve 2 works its way through the slots 8 and thecrevices between the bearing segments 3 on to the surface of the bushing4.

The invention operates substantially as follows: The spring I5 exerts agreater force against the blocks 9, I0 than the spring I9 as previouslydescribed. There consequently is a net resilient force urging the blocksapart. Thus, as wear occurs in the bearing, the segments 3 are movedoutward by the inclined grooves II, I2 engaging the V-shaped cam surface1 on the lugs 1.

As the blocks are progressively moved apart in compensating for thebearing wear, the springs 26 synchronously urge the wedges 25 furtherinto operative engagement with the wedges 21. This prevents the frictionsegments 3 from contracting once they have been automatically expandedas above described. The springl is thus relieved from the work ofmaintaining the segments 3 expanded and performs only the work ofactually expanding the segments.

After the bearing pin has been expanded a given amount, the expansion ofthe spring I5 and the corresponding compression of the spring I9 rendersthe forces of these two springs substantially equal. There then is nonet force urging the blocks apart. The bearing pin, consequently, can beexpanded no further. This limiting of the possible expansion of thebearing pin insures against any undue expansion which might causeexcessive friction in the bearing. The lessening of the expansivetendency of the bearing pin as the tensions of the springs I5, I9approach equality insures an adequate working clearance being maintainedafter the bearing has been initially worked in.

After the bearing pin has expanded to the limit above described, furtherwear would render the bearing loose. The lock nut assembly on the stemI6 may then be adjusted so as to lessen the tension of the spring I9.This enables the spring I5 to again exert an effective force urging theblocks 9 and I9 apart. The automatic expansion operation is thenrepeated exactly in the manner before described.

Fig. 4 illustrates a modified form of the invention in which the bearingpin is expanded manually to compensate for bearing wear. Partscorresponding to those described in the preferred embodiment areindicated by similar reference numerals bearing the sux :v.

The stem |69: has left and right hand threads therein engaging theblocks 9x and IO respectively. The bearing is expanded by loosening thelock nut 20:1: and turning the stem |61: in a clockwise direction by thesquare end IS. This moves the blocks 9:1: and Illa: apart thus expandingthe bearing segments 3x in the manner described in connection with thepreferred form. After the bearing pin is expanded the requisite amount,the lock nut 29m is again tightened locking the segments againstcontraction. The wedges interposed between the blocks 9 and I0 can beomitted in this modified form of the invention.

Having thus described the invention, what is claimed and desired to besecured by Letters Patent is:

1. A bearing pin including a plurality of circularly arranged bearingsegments; inwardly disposed V-snaped cam surfaces projecting from saidsegments; blocks cooperating with said cam surfaces and adapted to movesaid segments outward when moved apart; resilient means urging saidblocks apart and wedge means interposed between said blocks and arrangedto prevent movement of said blocks toward each other.

2. A bearing pin including a plurality of circularly arranged bearingsegments; inwardly disposed V-shaped cam surfaces projecting from saidsegments; blocks cooperating with said cam surfaces and adapted to movesaid segments outward when moved apart; resilient means urging saidblocks apart; and means for preventing further movement after saidblocks have been moved apart a predetermined extent.

3. A bearing pin including a plurality of circularly arranged bearingsegments; inwardly disposed V-shaped cam surfaces projecting from saidsegments; blocks cooperating with said cam surfaces and adapted to movesaid segments outward when moved apart; a spring urging said blocksapart; and a second spring adapted to be tensioned by the movement ofsaid blocks apart until its thrust is equal to the thrust of the firstspring.

4. A bearing including a plurality of circularly arranged bearingsegments; inwardly disposed V-shaped cam surfaces projecting from saidsegy ments; blocks cooperating with said cam surfaces and adapted tomove said segments outward when moved apart; resilient means urging saidblocks apart; a pair of wedges interposed between said blocks andarranged to prevent movement of said blocks toward each other when oncemoved apart; and spring means urging said wedges into operativeengagement with each other.

QUINTEN E. CONNER.

